<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>发送ajax请求</title>
</head>

<body>
    <script>
        //接口地址：https://api.apishop.net/common/weather/get15DaysWeatherByArea?apiKey=Z7fKbwu4694afed741ecbcd01531882f5d803bbc09b2dfb&areaID=4234234
        const p = new Promise((resolve, reject) => {

                //1.创建对象
                const xhr = new XMLHttpRequest();
                //2.初始化
                xhr.open('GET', 'https://api.apishop.net/common/weather/get15DaysWeatherByArea?apiKey=Z7fKbwu4694afed741ecbcd01531882f5d803bbc09b2dfb&areaID=4234234');
                //3.发送
                xhr.send();
                //4.绑定事件，处理响应结果
                xhr.onreadystatechange = function() {
                    //判断
                    if (xhr.readyState === 4) {
                        //判断响应状态码 200-299
                        if (xhr.status >= 200 && xhr.status < 300) {
                            //表示成功
                            resolve(xhr.response);
                        } else {
                            //如果失败
                            reject(xhr.status);
                        }

                    }

                }
            })
            //指定回调
        p.then(function(value) {
            console.log(value);
        }, function(reason) {
            console.error(reason);
        })
    </script>
</body>

</html>